Guitar free zone … the Agitator, the band Meins fronts, taking part in a sit-in at UCL, London. Photograph: Robbie Mailer-Howat

The last few months have proved one thing beyond doubt: that British teens and twentysomethings are far from apolitical. Some questions do, however, linger: as students go on the march and hostility to the cuts spreads, where are the musical voices channelling this new mood? If past generations of protestors were assisted by your Dylans, Strummers and Braggs, might they have any contemporary equivalents?

Meins and his two compadres, who are both drummers and co-vocalists, make music that undoubtedly chimes with the moment: fantastically impassioned stuff, full of a scattershot kind of dissent. Back in May, they released an admirably prescient first single entitled Let's Get Marching; it's now been followed by a glimpse of life in hard times called Give Me All That You Got. By way of proof that they are on to something, they lately performed at a run of protests – most notably, doing what Meins thinks may be the best gig of the Agitator's brief career, in front of the students involved in a recent occupation of University College, London.

Meins's songs draw on soul, gospel, the early spirit of hip-hop, and the kind of work-songs captured in pre-war field recordings; and to his credit, by way of separating himself from the herd, he refuses to use guitars. His model is "three voices and two drummers", and he has resolved to stick to it. As his press bumf puts it, the Agitator's aim is simple enough: "A new kind of music, nothing more than banging, stamping, clapping and voices . . . something anyone could do anywhere – on a march, at a protest, on the barricades."

I meet Meins, up for the day from Brighton, in an old-school pub in west London. He's pristinely dressed, articulate, in possession of an admirably clear agenda – and an unlikely back story. Meins is a native of Berwick-upon-Tweed, from a working-class household (his dad is a farm labourer, his mum a nurse) where politics was not often discussed. At the age of 15, he became a full-time musician, leading an indie quartet called Eastern Lane, who signed with Rough Trade, and were audibly fond of the Fall. "We had no absolutely no idea what we were doing," he says. They managed two albums before calling it quits, whereupon Meins dabbled in poetry, short stories and playwriting, releasing a barely noticed solo album, The Famous Poet Derek Meins.

His epiphany, he tells me, came courtesy of the financial crash, which caused his sudden immersion in stuff he had spent his life avoiding. "It was a coming of age thing, really," he says. "Moving away from my family and actually fending for myself – it was maybe like what happens to people when they go to university. I was becoming more socially aware, reading newspapers with more interest, and reading different sorts of literature." He mentions George Orwell, Noam Chomsky, and the Scottish writer and polemicist James Kelman. "The whole thing was almost an awakening for me: 'Oh my God, I've just spent the last 20 years not really thinking about anything apart from my own little bubble.'"

At the same time, he immersed himself in music he had barely experienced before, and reached a pointed conclusion about what most of his contemporaries were doing. "It seemed like more and more music was focusing on escaping from things," he says. Although he won't name names, the problem apparently lies in both "everything on daytime Radio 1" and "anything you'd hear if you went round venues in London". By contrast, he heard a world of possibility in the work of such hip-hop pioneers as KRS-One and Public Enemy. His vision of what to do next began to cohere.

The "no guitars" rule is, he says, non-negotiable. "We live in such remarkable times at the minute. To go hand-in-hand with that, you need to make music that's as radical as what you're saying. If you've got four guys standing there with guitars, it just draws it back into this massive landfill of people, just changing tiny little bits of something that people have been doing for 50 years."

Politically, Meins seems to be a work in progress. So far, his lyrics are a matter of exhortations and statements of intent ("It's a good day for a change of pace/ Stare at your problems straight in the face," goes a not untypical piece called Get Ready) rather than finger-pointing specifics. He says he knows he's not on the right, but bristles slightly when I'm trying to divine his feelings about the left, explaining that both the record of the last government and the simplistic pieties of revolutionary sects rather put him off the label. That said, the fact that his artwork draws on old-school socialist poster art serves notice of roughly where he's coming from, as do his broadbrush critiques of where the country is headed.

"We're stuck in the middle of something that people are finally getting really het up about," he says. "And that's amazing. But the worst is still to come. As far I can see, everything's been kind of subsidised over the last couple of years. Now there isn't the money to do that, so the people at the bottom are going to suffer even more."

Not the Christmas No 1

The critique may not be sophisticated, but it doesn't have to be: in keeping with his primary-coloured aesthetic, the Agitator's next single will simply be called No!. It will be accompanied by a campaign with the same theme; put simply, his underlying conviction is that, in times so brimming with urgency, the boldest messages are best.

Like any politically motivated musician who aims higher than busking, Meins is supported by a small-scale machine that, from a purist viewpoint, might threaten to endanger his integrity, and give off the odour of radical chic. The Agitator's manager is David Balfe, the former co-chief of Food, Blur's old record label; inevitably, their non-musical activities receive PR assistance.

Asked the same questions that have always dogged politically motivated musicians, Meins gives time-honoured answers. Doesn't he worry that the record industry's customary chicanery will cheapen his art? He answers in the same terms as Joe Strummer circa 1976: "It would cheapen it if this wasn't something I believed in. I'd be making this music anyway, whether or not it was being marketed. But I can't see anything bad that can come from it being on a bigger stage than, say, playing in front of 50 people in a pub."

An Agitator album will appear in spring; in the meantime, Meins tells me he has spent the last couple of days emailing the organisers of student occupations: "We're going to see if we can do a little tour of them." So what's the aim? To spark debate, yes – but what of commercial success? "I don't think there's any chance of me having a No 1," he says. "I don't even want it." What he says next amounts to the most concise of mission statements. "I want to make music that has a valid point."